import pandas as pd

df1 = pd.DataFrame(
    [{"r1": 'a', "r2": 1, "symbol": "s1"},
     {"r1": "b", "r2": 2, "symbol": "s2"},
     {"r1": "c", "r2": 2, "symbol": "s3"},
     {"r1": "a", "r2": 3, "symbol": "s4"}
     ]
)


def find_one():
    # fail
    r = df1["r2"]
    print(r)


if __name__=="__main__":
    find_one()